Operation Cat Drop
Operation Cat Drop is the name commonly given to an account, of uncertain veracity, about the delivery, by the United Kingdom's Royal Air Force, of cats to a remote village in Sarawak, Borneo. The cats were delivered in crates, dropped by parachute, as part of a broader program of supplying cats to combat a plague of rats. The cat population had previously been reduced as an unintended consequence of spraying DDT for malaria control. The story, often with various elaborations is often told as an illustration of the problems that may arise from well-intended interventions in the environment, or of unintended consequences more generally.
It is not clear whether the events of the Operation Cat Drop story actually transpired as the story is commonly told or if the cats were ever delivered by parachute. While cats are indeed unusually susceptible to the toxic effects of DDT, and cat die-offs were a not unheard of side effect of malaria control operations, many aspects of the story have been called into question. For example, it was probably dieldrin rather than DDT which was used for malaria control in the region and caused numerous cat deaths.